Canister plug



FIG. 1 is a top, front, right side perspective view of a canister plug showing my design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a rear elevational view thereof; and,

FIG. 5 is a top plan view thereof. 

The ornamental design for a canister plug, as shown and described. 